Kingsford, R.T., Bino, G. and Porter, J.L. (2017). Continental impacts of water development on waterbirds, contrasting two Australian river basins: Global implications for sustainable water use. Global Change Biology

Author/s associated with the CES:

Richard Kingsford

Gilad Bino

John Porter

Abstract

The world’s freshwater biotas are declining in diversity, range and abundance, morethan in other realms, with human appropriation of water. Despite considerable dataon the distribution of dams and their hydrological effects on river systems, there arefew expansive and long analyses of impacts on freshwater biota. We investigatedtrends in waterbird communities over 32 years, (1983–2014), at three spatial scales intwo similarly sized large river basins, with contrasting levels of water resource devel-opment, representing almost a third (29%) of Australia: the Murray–Darling Basin andthe Lake Eyre Basin. The Murray–Darling Basin is Australia’s most developed riverbasin (240 dams storing 29,893 GL) while the Lake Eyre Basin is one of the less devel-oped basins (1 dam storing 14 GL). We compared the long-term responses of water-bird communities in the two river basins at river basin, catchment and major wetlandscales. Waterbird abundances were strongly related to river flows and rainfall. For thedeveloped Murray–Darling Basin, we identified significant long-term declines in totalabundances, functional response groups (e.g., piscivores) and individual species ofwaterbird (n = 50), associated with reductions in cumulative annual flow. These trendsindicated ecosystem level changes. Contrastingly, we found no evidence of waterbirddeclines in the undeveloped Lake Eyre Basin. We also modelled the effects of the Aus-tralian Government buying up water rights and returning these to the riverine environ-ment, at a substantial cost (>3.1 AUD billion) which were projected to partly (18%improvement) restore waterbird abundances, but projected climate change effectscould reduce these benefits considerably to only a 1% or 4% improvement, withrespective annual recovery of environmental flows of 2,800 GL or 3,200 GL. Ourunique large temporal and spatial scale analyses demonstrated severe long-term eco-logical impact of water resource development on prominent freshwater animals, withimplications for global management of water resources.